Monitored and controlled conditioning and exercise method for animals



United States Patent 72] lnventors Max B. Kirkpatrick Anchorage, Alaska;Andrew G. Harvey, and John M. Sparks 111 Box 1509, Wickenburg, Arizona85358 [21] Appl. No. 683,719 [22] Filed Nov. 16, 1967 [45] Patented Dec.1, 1970 [54] MONITORED AND CONTROLLED CONDITIONING AND EXERCISE METHODFOR ANIMALS 18 Claims, 10 Drawing Figs.

[52] U.S.Cl 119/29; 73/379: 119/158; 128/205, 128/206; 272/57 [51] Int.Cl ..A01k 15/00 [50] Field ofSearch 128/25,

Primary Examiner-Aldrich F. Medbery Attorney-Strauch, Nolan, Neale, Niesand Kurz ABSTRACT: A method of producing an animal such as a race horsecapable of optimum performance comprises selection of an animal havingan adequately large heart at an early age so that training may startduring the formative years, placing the animal on a known analysishighly digestible diet and making blood and related analysis todetermine the normal equilibrium of the particular animal in respect tovarious physiological characteristics involved in conditioning andexercise, checking the animal for. normal weight during this equilibriumperiod, and conditioning the animal by causing it to cyclically undergoswimming periods of vigorous exercise spaced by partial recoveryintervals, all the while during such conditioning monitoring the animalsheart action to determine the timing of the exercise periods andrecovery intervals to thereby prevent the heart rate from rising abovesafe values during the exercise periods and insure that each exerciseperiod of a cycle is started before full recovery to normal heart rate,and monitoring the animal's weight by measuring it at the beginning ofeach day's exercise to correlate it with normal and the animals diet andenable the conditioning cycle to be terminated in time to prevent theexistence of excessive energy requirements which might cause excessivetissue damage.

Patented Dec. 1, 1970 INVENTORS MAX 5. K/RKPATR/CK ANDREW G. HARVEY JOHNM. SPARKS, ZZZ

029M flaw; (W0 m,

ATTOR/VFYS BACKGROUND AND SUMMARY OF lNVENTlON The invention relates tothe selection and controlled conditioning of animals, particularly racehorses although most basic aspects may be applied to humans.

Prior to the invention it has always been common practice to conditionand train horses for racing using traditional methods which vary widelybetween individual trainers but in all of which the horses are exercisedby actual running and their condition ascertained only by visualobservation and/or by feeling chest and leg muscles. Experience hasshown that horses undergoing such training are likely to accidentallyphysically injure their legs in one way or another during running,usually because of early fatigue due to poor or inadequate conditioning.Furthermore, there is no way to accurately discover during such trainingwhether the horse is being exercised excessively or in such manner as tocause internal damage.

As a result of these haphazard training methods, many capable horsessuffer premature injury and never reach the track, and many of those whodo reach the track are so overtrained as not to be in optimum conditionat the time.

Diets have long been known to be important or even essential, and againthere are many different diets for race horses. To our knowledgehowever, none of these diets have been preceded by a physiological studyof the particular animal including a determination of any dietdeficiency in the food and correction of that deficiency prior toconditioning.

The invention provides for the first time for the proper selection ofanimals, the most advantageous mode of preparing the selected animal foractual conditioning, and an optimum substantially injury-freeconditioning exercise program wherein the animal is continuallymonitored to prevent excesses, and such is the major object.

An essential object of the invention is to provide controlled cyclicconditioning exercise of the animal monitored to prevent overtraining,this comprising vigorously exercising the animal during periods of highheart beat near but under safe values determined by test on theparticular animal, such periods being spaced by nonexercising recoveryintervals during which the heart beat is allowed to drop to a safe valuefor resuming the exercise, while continually monitoring the animal'sheart action to determine the length of these periods and intervals. Anattendant object of the invention is to monitor the animals weightduring conditioning, usually weighing it at the beginning of each day'sexercise period to correlate the loss of weight caused by exercise withfood intake and prevent muscle and like tissue deterioration due tooverexercise.

The invention will be explained in detail with regard to race horsetraining which isits preferred application.

The first step is the proper selection of a colt. It is preferable toselect colts at the age of 6 months. it is known that a horses heartsize changes between birth and the age of 18 months more than at anyother time. For this reason, it is important under the invention thatconcentrated exercise occurs from weaning (6 months) to age two. Howeverthe invention may be applied to horses of any racing age. For purposesof simplicity the term includes colts.

The two major factors in selection are conformation and size of theheart as determined by observation of an electrocardiogram andmeasurement of the width of the QRS complex. The QRS width is the timean electrical impulse takes to travel through the muscle mass of theventricles and this width is directly proportional to the muscle mass ofthe heart ventricles and therefore it is a measure of heart size. ThisQRS width would be the final determination as to whether or not the coltis selected or rejected, because normally only horses with defect-freelarge heart size may become efficient winning race horses. The selectedhorse is preferably placed under observation on a basic properlybalanced diet formu:

lated for the purpose ofproviding as much nutrient to the horse aspractical from a conventional ration point of view. Once on this ration,the animal's teeth are floated. he is wormed if necessary, he is givenhis general regime of vaccinations for the prevention of the usualcontagious diseases, and is allowed to become acclimated to hissurroundings while being on this diet for approximately a week to 10days. The reason the animal is on the diet for this period is that itallows his metabolic system to bring his blood chemistry into balancewith the particular ration that he is on and in the particularenvironment in which he is present.

Once this horse reaches this state of normal equilibrium as it will becalled, his normal weight is determined and several basic blood chemicalanalyses are performed to establish the individual horse's normal rangefor each biochemical test. These tests are as follows: total protein,albumin, globulin, SGOT, phosphorus, alkaline phosphatase, bilirubin,calcium, potassium, sodium, chloride, lactic acids, hematocrit, andhemoglobin.

Following is a brief explanation as to the reasons these chemicalanalysis and their use in the conditioning period. in general, thesesreasons are twofold. One is that they indicate the balance of the rationor nutrition that is being utilized by the animal, and secondly theyserve as an indicator to determine whether or not any tissue damage isoccurring during the conditioning period to determine, prior to clinicalevidence, whether the horse is being overconditioned.

Exercise is a factor in maintaining an efficient hemopeotic system orblood system; and training and racing lead to destruction of red bloodcells, which in turn should serve as a stimulus for the production ofnew red blood cells. One would therefore expect to see an increase inserum bilirubin and a slight rise in new blood cells on a horsebeginning training. From then on, under optimum conditions, thesefactors should reach a steady state, and any variations would requirefurther investigation. At later stages of training, should the bilirubinremain high or show a rise, the probability of excessive exercise wouldbe considered. A closer examination would be made of the animalsclinical appearance and his training record.

SGOT levels can be used as an indication of quantity of work beingperformed at any stage of training and muscle damage during training.During training, it is quite common to find marked, raised levels whichrapidly return to normal as training and racing progresses. This is alsoseen in the fat animal when its training is too hurried, owing to amistaken impression that the fat represents condition. A rise in SGOTlevels, at the stage of normal condition, may indicate problems otherthan training. They should be considered important and the horse shouldbe reevaluated.

Slightly to markedly raised alkaline phosphatase levels are consideredindicative of theeffects of growth hormone, and this is especially truein the 6 months to 3 year old animals. Should energy requirements at thegrowth period exceed the caloric intake, there will'be naturally astunting of the individuals growth. It is important then to carefullytrain these young animals in proportion to the amount of calories theyobtain from the nutrition. Under conditions of increased stress in theseanimals, an excessive glucocorticoid production results. Proteincatabolism and negative nitrogen balance occurs. This can be seenclinically in the form of reduced muscle mass, and very often causeshorses to have a faulty gait. But if the phosphate and alkalinephosphatase levels are watched during an extreme exercise, then proteincatabolism and negative nitrogen balance can be prevented.

It is especially true that a fall in serum proteins, especially thealbumin fraction, is noticed in animals whose protein in take is lessthan normal, and also in whose nutritional diet the carbohydrate is at alow ebb or ineases where the exercise caloric requirement exceeds thecaloric intake. ln either of these cases the protein is broken down dueto the animals increased requirement for energy, resulting in situationsmentioned above. A fall in levels of protein in the serum is always adanger sign and suggestive of failure to adapt to training in mosthorses.

The sodium and chloride measurements of the serum are important withrespect to the animal s maintenance of proper fluid balance. Theseanimals work very hard and sweat profusely, and in some instances areworked to the point where they become excessively dehydrated. Knownsodium and chloride levels will help prevent this.

The lactic acid level is important and will be studied more extensivelythan any of the others in regard to the evaluation of this chemical atvarious periods of exercise and during various stages of exercise. It isknown that increased lactic acid level is one of the causes ofdestruction of muscle tissue during intensive exercise, causing lamenessin horses that tie up due to fatigue as a result of improperconditioning. With proper study of lactic acid simultaneously withinterval swimming exercise under the invention much can be learned; andhorses can be helped in their conditioning.

The hemoglobin and hemotocrit are important tests to tell us relativelyhow many red blood cells are present per given volume of blood, as wellas how much hemoglobin or oxygen carrying capacity these red blood cellshave.

Two other tests advantageously used in this particular regime ofbiochemistry are the potassium level and the carbon dioxide level of theblood. Potassium is an element which is very important for heartfunction. it also is excreted occasionally when glucocorticoid activityis at a high level in the body. Carbon dioxide level will be utilized asa measure of oxygenation efficiency of the blood as well as anindication of acid base balance if total CO is studied.

Once the normal physiological values in the above are obtained on eachindividual horse, and his electrocardiogram studied for acquainting theveterinarian with the size of the heart as well as the examination ofthe T-wave amplitude and position. When horses are completely out ofcondition, the T- wave is positive in charge and high in amplitude on aunipolar base apical lead, at rest. As the horse becomes conditioned, T-waves become negative in polarity and greater in amplitude in thenegative direction. This is an important determination as to whether ornot the horse is fit from the electrocardiogram standpoint.

Once the horses physiological values are known and understood, andnutrition is balanced, the horse begins active conditioning with theswimming exercise cycle program. The horse is preferably exercised inthe following manner. He is placed on an elevator platform above a bodyof water and restrained from appreciable movement front, rear andlaterally, care being taken not to physically restrain in any way thelegs or any muscles used in swimming. A heart condition meter in theform of an electrocardiograph and a heart rate meter are connected tohis body by means of suction devices as will appear. His heart action iscontinually monitored during the entire program. He is lowered into thewater until he is forced to swim and so remains until his heart isobserved to attain a steady rate of approximately 200-225 beats perminute depending on the horses normal. Instantly, at that point, thehorse is raised out of the water far enough so that he may breathe asfreely as possible and stop swimming. This is preferably done by raisingthe platform until he can stand on it. He is raised to such height thatthe lung cavity is completely out of the water so that there is nohydrostatic pressure against the lungs when he is in a state of oxygendebit. The recovery interval now starts. The heart rate meter andelectrocardiogram are watched until his reducing heart rate reaches apoint on the electrocardiograph where the T-P base line becomesdiscernible and the T-wave shape indicates the start of reversal. Theheart rate at this point may be in the neighborhood of ll40 beats perminute depending on the individual. Either meter maybe used to determinethis period. When the individuals heart rate reaches the low point therecovery interval is over and he immediately is returned to the water bylowering the platform so that he is again forced to swim until his heartrate arrives at approximately 200-225 again. in

practice, the length of this recovery interval is carefully noted, asrecovery rate is a barometer of the horses condition. The whole sequenceis repeated cyclically to the end of the exercise.

Once the horse enters the platform, he is automatically weighed. Thehorse is weighed every day or every time he swims a cycle. The reasonthat the horse is weighed every day or at the beginning of each swimcycle is to determine whether or not the amount offood intake or caloricintake in his diet is equaling the amount of energy calories required intraining. This monitoring of the horses weight provides a gross means ofcorrelating the total amount of energy supplied by the food compared tothe total amount of energy utilized by the exercise. The horse alwaysloses some weight during a swim cycle due to perspiration and like fluidloss but this is usually compensated by drinking water after theexercise. The foregoing monitoring observes any real change in weightdue to actual loss of body mass.

in accord with the weight monitoring, the swim cycle may be altered ifthe real loss of weight exceeds the food intake which is a signal thathe is drawing reserve protein and other substances out of storage in hisbody. Therefore, the number of times a horse goes in and out of thewater may be determined by maintenance of a desired weight. After a swimexercise cycle the rate of recovery of the horses heart heat back tonormal is measured and noted.

The horse is trained in this manner, depending upon the observedcondition ofthe animal on a daily basis. Usually there is a swimmingexercise cycle each day during conditioning. At the end of this time,the horse graduates from the training facility and may be moved to amaintenance facility at a track. The maintenance facility is equippedwith a portable device wherein he may be lowered into a body of waterfor monitored swimming exercise as before. The horse can be worked,raced, trained to be rated, trained to break properly from the gate,well as become accustomed to the natural surroundings of a racetrack.When the horse graduates to the maintenance facility, his swimmingexercise is interspersed with various running workouts. The horse maynot be swimming every day, but his heart action will be continuallymonitored at a periodic intervals to determine if the horse maintainsproper condition. if not, he will be returned to the conditioningfacility.

With this particular method of conditioning horses, a horse may alwaysbe maintained in condition from the time he is 6 months of age until heis through with his racing career, for all practical purposes. it doesnot damage the horse to be kept in constant condition as long as itneeds to be kept in condition and can run. it is actually easier for ahorse to be kept in condition rather than to let it down at the end ofeach racing schedule but the main advantage is heavy exercise can bemaintained without damage to the horses legs. The main a va'ntage forswimming the horse in a pool at the track is that should he become lame,or should he become injured, his condition can be maintained duringrecovery from the injury while at the track, if it is necessary, ratherthan return him to the training facility.

Only a certain number of calories can be supplied to a horse in theconventional diet. The invention contemplates that a high-energypurified diet be provided so that a large number of calories may be putinto a horse with a small amount of feed. This can be done on acontinuous free choice basis rather than interval feeding. Thus thehorse would have at his access, during a race, internal energy that hewould not normally have if he were trained and raced under conventionalmethods.

The invention contemplates putting a high number of calories into thehorses with the result that they expend high energy when called upon ina manner which would make them more fit and give them capacity for atremendous amount of endurance that horses have not approached whentrained by conventional methods.

One of the major advantages in swimming a horse for exerelse is that ahigh heart rate can be obtained and safely mainmore venous capillariesfor the return of carbon dioxide and lactic acid during exercise,thereby making a more efficient machine which will operate at greatercapabilities, more'efficiently, for longer periods.

BRIEF DESCRIPTION OF DRAWINGS FIGS. la, 1b, 1a, 1b, 1a", and b" arediagrammatic views showing the monitored interval swimming exerciseprogram according to the invention;

FIG. 2 is a diagrammatic view showing preferred placement of themeasuring instrument leads on a horse undergoing the interval swimmingexercise program of FIG. 1;

, FIG. 3 is a specimen section of an electrocardiograph taken on a horseat rest,

FIG. 4 is a specimen section of an electrocardiograph taken during anactual exercise period of a vigorously swimming horse; and

FIG. 5 shows a preferred suction cup structure used for attachingelectrocardiograph or heart rate meter leads to the horse during theexercise program.

PREFERRED EMBODIMENTS The invention in the preferred embodimentscontemplates correlating adequate controlled exercise and diet of aselected animal. An animal subjected to exercise will lose weight asfood is converted to useful energy. Properly controlled the exercisewill utilize the food contained in the animal's diet by converting it toaccomplish'body building and using functions; and depending on'the diet,such conversion will be more or less efficient. Excess'exercise willbreak down difficult to rebuild muscle and body tissues and result indeteriorated condition with attendant loss of weight. In the inventionthe amount of exercise'is so controlled that such deterioration isprevented, and this is usually done by continually monitoring theanimals heart rate and weight during exercise in accord with informationderived from the foregoing analyses and tests which will indicate theacceptable heart rate and exerciseweight factors for that animal.

The invention includes the discovery that the optimum manner ofcontrollably exercising an animalsuch as a horse for racing is swimming.This is mainly because swimming utilizes essentially all of the majormuscles used in running, and swimming takes place in an environmentwherein the horse is least subject to injury.

Swimming moreover is an exercise which causes a relatively greatincrease in cardiac output to supply needed oxygen to the muscles.Several factors other than the exerciseitself, namely, increasedheatloss, respiratory stimulation, and pressure of the water, areresponsible for the greater cardiac response in this type of exercise, Alarge heart will be capable of handling most increased venous returncaused by vigorous exercise without appreciable increase in heart rate,and therefore by increasing the rate of beat of such a heart duringviolent exercise such as strong swimming it maintains a constant highoutput adequate to handle the corresponding increased venous return, andso increase the totalcirculation with more blood being delivered to thecapillaries to supply oxygen to the muscles for sustained effort.

In conditioning a horse as shown in FIG. 1, the animal is placed on aplatform 11 elevated above a confined body-of water indicated at 12 andrestrained from lateral, forward and rearward movements of the platform.This restraint is applied to the upper part of the body as by strapswell above the legs, or by connecting the tail to a stable bar behindthe horse, so

that there is no mechanical interference with normal leg movement orshoulder and upper rear leg muscles or respiratory action duringswimming.

The sequence of FIGS. la-lb" diagrammatically illustrates the cycle ofswimming exercise under the invention. Position a indicates the start ofthe exercise period. This position may be above water level to enter thehorse directly onto the platform.

The platform, with the animal thereon, is lowered gradually into or inthe water until at the FIG, 1b position indicated at 11 submersion issuch that the animal must swim to remain afloat. Swimming tends .topropel the animal forwardly, but this movement is prevented by the frontrestraint so that effectively the animal remains longitudinallysubstantially in the same place while the legs move through the water.

While the animal is swimming its heart is closely monitored. The effortof swimming will cause the heart rate to rise, in proportion to theenergy being exerted, and the invention includes discovery that asustained high heart rate above a cer tain safe value, which value willbe indicated for that animal by the foregoing physiological analyses andelectrocardiograms, will result in harmful fatigue rather thanbeneficial conditioning.

The heart action is constantly measured during the exercise cycle by aspecial combination of novel body attached electrodes shown at 13 and 14and an electrical instrument 15 capable of detecting and measurablyindicating the very small generated voltagesincident to heart action, inthe neighborhood of one to three millivolts, such as anelectrocardiograph or a heart rate meter. As will be described, theelectrodes are special suction cups attached as by line 16, 17 to anexternal source of vacuum 18.

It is absolutely essential that there be no extraneous electricalsignals to very 'or mask the potentials generated by heart muscleaction. Therefore the electrodes 13 and 14 are preferably attached tothe horse's body at the illustrated points in FIG. 2 where adjacentmuscular activity is minimum notably near the top of the front shoulderand at the underside of the body near the front leg. 'It is furtheressential that the electrodes make good unvarying contact with thehorse's body, and that is the function of the external vacuum which inexercises to date indicate that a vacuum of about 25 inches of mercuryis satisfactory to anchor the electrodes to the body so as to preventany static generating movement thereof relative to the body even whenthe horse is swimming vigorously.

As shown in FIGS each vacuum line 16 (or 17) is a vinyl or likenonconducting plastic tube 21 fitted upon a stainless steel collar 22welded air tight into an aperture in a shallow noncollapsible stainlesssteel cup 23. The end of a stainless steel wire 24 is welded at 25 tocollar 22, and the wires 24 emerge from the tubes 21 in an insulatingsheath 20 for connection to meter 15, so that the wires 24 areelectrically insulated from each other between their respectiveelectrodes and the meter. Preferably the tubes 21 of lines 16 and 17 arejoined to a single tube 26 leading to a vacuum source 18, so that thevacuum is connected to simultaneously act on the electrodes.

The importance of the external suction source lies in its ability toexert sufficient force. to properly anchor electrodes 13 and 14. Suctionbulbs have been proposed for electrodes in human electrocardiography,but such would not be adequate for attachment to vigorously exercisinghorses. We know of no instance where electrocardiographs have been takenof vigorously exercising. humans during exercise, so that the problemssolved by this phase of the invention have never been presented orrecognized.

In actual practice it was discovered that the presence of chlorine andlike substances in Y the water containing the swimming horse resulted insufficient electrolytic action at electrodes containing junctures ofdissimilar metals to produce misleading signals in the meter leads.Hence care is taken in the invention to eliminate this difficulty, and acurrent solution is to use the same metal along the entire conductivepath between the horse's body and the meter 15. In practice the suctioncups 23 and collars 22 are armed of 316 stainless steel about 0.035inches thick, and wires 24 are 316 stainless steel. Welding is done witha 316 stainless steel welding rod. Therefore the conductive metalcomposition is uniform along its entire length, and no electrolyticeffects are present.

Referring to FIG. 5, it will be noted that application of vacuum to tube21 results in the skin 27 of the horse being pulled into closeconformity with the interior of the cup 23, with the sharp annular edge26' of the cup indenting (but not cutting) the skin. This provides agood locking attachment which does not change position or becomedetached when the horse is swimming; We believe that such strongattachment of the electrodes and selection of regions of the horses bodywhich undergo little movement when the horse is exercising mutuallycontribute to the clarity with which the heart action signals arereceived during exercise.

Referring again to FIG. la, a weight indicating system isdiagrammatically indicated at 28 connected to a scale dial 29 which canbe calibrated to indicate the horses weight directly. Weight readingsare usually taken only when the platform is free of the water.

Any suitable weighing apparatus may be used and in fact the exactapparatus is independent of the method phase of the invention hereinclaimed. A preferred embodiment of the weighing apparatus is disclosedin our application U.S. Pat. Ser. No. 712,183, filed Mar. 11, 1968wherein the scale dial is activated by hydraulic pressure effectivelysupporting the platform 11.

The measuring system including attachment of electrodes 13 and 1 i isplaced usually when the horse enters to position FIG. 1a and is innormal equilibrium. Then'his heart rate and weight are measured, and heis lowered to swimming position F 16. lb during which the electrodesremain attached.

ln position b monitoring of the heart rate continues. As soon as themeasured heart rate reaches the upper limit range (200- 225beats/minute) the platform is raised toward position lll until the horsecan find footing, is not longer swimming, is standing on the platform asshown at P16. 1a and is breathing easier as above explained. Now therecovery interval starts and during this interval constant monitoring ofthe heart rate continues and the horse's rate of recovery is noted. FIG.4 shows an electrocardiograph of the violently exercising horse, theT-wave being positive.

When the lowering heart rate reaches a predetermined range, usuallyabout l40beats/minute indicated on the heart rate meter, or wheninversion of the T-wave from positive to negative appears as shown inFIG. 3 becomes discernible on an electrocardiogram, the platform isagain lowered as at FIG. lb until the animal is forced to resume hisswimming. The duration of the recovery interval is noted.

The foregoing is repeated several times, the animal being thus violentlyexercised by swimming for successive periods at high heart beat levelsand allowed to partially recover between periods of exercise.

During conditioning, the horse is given this swimming exercise cycle onthe average of about once a day and he is weighed each day about thesame time. The swimming exercise is varied if the change in weightindicates the animal may be drawing on reserves while exercising. Astraining progresses and the horse becomes conditioned it will be notedthat the exercise period in cycle time gradually increases and therecovery interval decreases which is an indication that endurance isincreasing. Each exercise period lasts a reasonable time, usually about3-10 minutes depending on the horse and his current condition. Theconditioning period lasts about 3 to 6 weeks normally, but this may varyfor individuals.

The foregoing described conditioning method is safe and humane, and itunexpectedly improves a horses endurance capabilities. Constantmonitoring of the heart rate insures that the horse never reaches thefatigue point between recovery intervals. Continual monitoring ofrecovery is equally important. The quicker the horses heart rate dropsfrom 200-225 to l40175 during a recovery interval between swimmifigperiods the better the horse's condition. The quicker the he ses raterecovers to the equilibrium normal following the exercise of aconditioning. cycle, whether the exercise be swimming or running, thebetter the horses condition.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

We claim:

1. in a method of controllably conditioning an animal for periods ofsustained optimum physical effort such as racing, the steps ofexercising said animal by swimming during periods that are spaced bynonswimming recovery intervals during which the heart rate of the animalis allowed to reduce toward but not to normal, and monitoring the heartaction of said animal continually during said periods and intervals,said monitoring step comprising continually observing the instantaneousheart rate of said animal during said periods and intervals to preventrise of said heart rate above a predetermined safe maximum range duringsaid periods and to start each succeeding period substantiallyimmediately following a recovery interval at a point where the heartrate of the animal is in a relative high range as compared to normal butsafely below said predetermined maximum range so that during theexercise periods following the initial period the animal exercises in arelatively high above normal heart rate condition.

2. The method defined in claim 1, including the step ofmeasuring theduration of each recovery interval for determining the animals recoveryrate during exercise as an indication of the condition of said animal.

3. The method defined in claim l, including the step of determining theheart action recovery rate of said animal following an exercise cycle asan indication ofthe animals condition.

4. In the method defined in claim 1, said monitoring step comprisingcontinually observing the instantaneous heart rate of said animal duringsaid periods and intervals to prevent rise of said heart rate above apredetermined safe maximum range during said periods and to resume eachperiod following a recovery interval at a point where the heart rate ofthe animal is in a relative high range as compared to normal but safelybelow said predetermined maximum range so that during the exerciseperiods following the initial period the animal exercises in arelatively high heart beat condition.

5. 1n the method defined in claim 1 wherein the animal is a horse, eachsaid period being terminated when the heart rate of the horse rises to asubstantially sustained value within the range of about 200-225heartbeats per minute and each said interval being terminated when theheart rate of the animal drops to a substantially sustained value withinthe range of about heart beats per minute.

6. The method defined in claim 1., wherein said animal is monitored byan operating electrocardiograph during said periods and intervals.

7. The method defined in claim 1, wherein said animal is monitored by anoperating heart rate meter during said periods and intervals.

8. 1n the method defined in claim 1, said animal being placed on aplatform wherein it is restrained against appreciable forward, rearwardor lateral movement without interferring with respiratory action or thelegs or swimming muscles, which platform cyclically is lowered into abody of water sufficiently that the animal must swim to stay afloatduring the exercise periods and raised sufficiently to enable the animalto stand thereon during said recovery intervals.

9. 1n the method defined in claim 1, said monitoring step including thesecure attachment of at least one electrical potential measuring lead toa surface region of the animal's body that undergoes little or no musclederived movement during exercise.

10. In the method defined in claim 1, said monitoring step including thesecure attachment of at least one electrically conductive suction-cupelectrode to a surface region of the body of the animal, and applying anexternal source of vacuum to said cup.

11. In the method defined in claim 1, the steps of determining thenormal heart rate and weight factors for a particular animal prior tosaid conditioning steps.

i2. in the method defined in claim 1, the length of each recoveryinterval being determined by recovery of the animal to a predeterminedhigher than normal heart rate range and serving as an indication of thecondition of said animal.

13. In the method defined in claim 1, the step of measuring the heartrecovery rate of the animal to normal after an exercise cycle as anindication of the condition of-said animal.

14. A method for training animals as for racing and accomplishing anexercise session comprising: the application of means to an animal forsensing heart cycle action, causing said animal to exercise strenuouslyby swimming in place while observing the animal's heart rate duringexerciscand continuing said exercise until the heart action of theanimal reaches a safe predetermined maximum high rate range, thenresting the animal for a first nonswimming recovery interval duringwhich observation of the animals heart action is continued until saidrate decreases and until a partial recovery condition of the animal isapparent from said observation, said partial recovery being denoted byreturn of said heart rate to a range that is appreciably below saidmaximum but is appreciably above the normal of the animal andsuccessively repeating said steps of exercise until the heart rate azain approacies said maximum rate range and resting the annnai, eachCXJYCiSC period after the initial period being started while the animalis in a partial recovery condition.

15. The method defined in claim 14 wherein said animal is a horse andthe maximum heart rate is the range of 200-225 cycles per minute.

16. The method defined in claim 14. wherein observation of the animalsheart rate is accomplished by attachment of an electrocardiographproducing a continuous record of heart action, and said partial restcondition is noted from the electrocardiograph.

17. The method defined in claim 14, wherein the animal is forced to swimduring the exercise periods and is allowed to remain stationary duringsaid rest periods.

18. A method of controllahly conditioning horses for periods ofsustained physical effort such as racing comprising the immediatelysuccessive steps of exercising the horse by swimming in place for aperiod while continually monitoring its heart action, terminating saidperiod when the heart rate of the swimming horse substantially attains amaximum safe high range by providing a support on which the horse maystand during a recovery interval wherein its heart rate is allowed toreduce toward normal, continuing to monitor said heart action during therecovery interval, and immediately removing said support to start afurther swimming exercise period as soon as said reducing heart rate hasreached an exercise range appreciably below said maximum safe range butwell above said normal.

